July 2nd marked the 70th anniversary of one of the great mysteries of the twentieth century. On that day, celebrated aviator Amelia Earhart disappeared without a trace. Interest in the woman and the mystery persists to this day.

Visitors to the National Air and Space Museum in Washington continue to seek out information about Amelia Earhart. "Earhart's disappearance has certainly kept her name in the public eye," says curator Dorothy Cochrane. In fact, 70 years after her disappearance, Earhart is still considered the world's most famous woman pilot.

In the 1920s and 30s - the golden age of aviation - when men like Charles Lindbergh were breaking records and making headlines, Amelia Earhart proved she could compete on an equal footing. In 1932, five years after Lindbergh made his groundbreaking solo flight across the Atlantic, Earhart did the same. "And she was also only the second person to solo, which a lot of people don't realize, after Charles Lindbergh did it in 1927," says Cochrane.

National Air and Space Museum curator Dorothy Cochrane says Amelia Earhart was both a pioneer for women's rights and a pioneer aviator. Many of her flying records were firsts for both genders. Earhart was the first person to fly solo from California to Hawaii, from Los Angeles to Mexico City and from Mexico City to Newark.

In 1937, six years after Wiley Post circumnavigated the globe, Earhart set out to become the first woman to fly around the world. "She wanted this to be her last great, exploratory, record-breaking flight," says Cochrane.

Earhart was flying a new aircraft, the Lockheed Electra, which was loaded with the latest technology. The whole world was following her progress, Cochrane says, "because she did do a flight around the equator, which is the longest way you can go around the world."

Earhart and her navigator, Fred Noonan, were making the 46,000-kilometer journey in hops, and had only two more to go. They were flying from Lae, New Guinea, to Howland Island, a distance of 4100 kilometers. The U.S. Coast Guard cutter Itasca was anchored off-shore to help guide them in, and maintained radio contact with Earhart.

"Her final transmission, she says 'I am near you. I am on you but I cannot see you. I'm following a line of position that is near Howland Island.' And the signals were strong," says Cochrane. "That is the clearest evidence we have that she was near Howland Island, but could not find it."

In order to accommodate more fuel for the long flight, Earhart had decided to take only a radio transmitter with her, instead of more advanced equipment that may have helped her hone in on the Itasca's signal. "She compromised herself with this equipment, leaving it behind, and that is a major contributing factor to her disappearance," Cochrane says.

After a massive search, the plane and its crew were declared lost at sea three weeks after it disappeared.

Almost immediately, people began to speculate about what happened. There were theories that Earhart and Noonan were captured by the Japanese military and possibly executed as spies, in the months leading up to World War Two, or that they landed on an uninhabited island and died waiting to be rescued.

But National Air and Space Museum curator Dorothy Cochrane says she believes Earhart's plane ran out of fuel and crashed into the Pacific Ocean. "All of the different areas where she is said to have landed have been explored. So if we're going to find anything it is going to be about 17,000 feet [27,000 kilometers] down at the bottom of the Pacific Ocean not too far from Howland Island."

Until that evidence is found, there will always be those who believe Amelia Earhart did not perish at sea - and the mystery of her fate will endure.